The present invention relates to a mold construction for the manufacture of parts of thermoplastic material, the mold comprising two die elements, each of which is adapted to replaceably receive and support a die-insert plug, and the mutually facing surfaces of the insert plugs determining the shape of the part to be produced.
Such molds are used for the manufacture of parts by compression-molding or by injection-molding. The latter is particularly desirable since it enables extremely short cycle times and thus high cost-effectiveness. Furthermore, the injection-molding process permits a drastic reduction in the capital investment for a mold through use of so-called standard molds.
Such a standard mold consists of two die elements (or forces) which are clamped together by die-clamping mechanism of the machine. Each die element carries a die-insert or force plug, and the mutually facing surfaces of these plugs determine the shape of the part to be produced. In this connection, each insert plug is in form-locked relation to its supporting die element. If a different part is to be produced, the insert plugs are changed. However, this changing process requires a very long period of time, due to the form-locked connection between each die element and its plug. Change times of several hours are still considered normal.